Grinding-machine for belt-knives



L.'G'. KNOWLES. GRINDING MACHINE'FOR BELT KNIVES.

APPLICATION FILEDIAUGIZZI I9I9. I

Patented June 7, 1 921.

UNITED STATES PATENT OFFICE.

LLOYD G. KNOWLES, or BEVERLY, MASSACHUSETTS, .essrc-non TO- nnr'rnn SHOE MACHINERY CORPORATION, or rnrnnson, NEW JERSEY, A CORPORATION on NEW JERSEY.

Specification of Letters Patent.

GRINDING-IVIACHINE FOR BELT-KNIVES.

Patented June '7, 1921.

. The invention is illustrated as embodied in a machine of the type having an endless band or belt knife together with rolls which feed the work to and against the cutting edge of the knife. In such a machine it is essential, for best results, to maintain c0ntinually the closest possible relationship between the cutting edge of the knife and the bite of the feed rolls in order tosplit the leather uniformly. For the same reasons it is essential that the knife be kept uniformly sharp. In machines of the character described it is customary to employ the upper run or stretch of the belt knife to split the material fed by the rolls and to provide one or more grinders to act on the lower run or stretch of the belt, and to provide adjust ing means to compensate for wear of the knife.

One of the objects of the present inven- 7 as the grinding wheels wear.

Further features of the invention consist in means for adjusting the feed rolls simultaneously with and in the same direction as the flat-faced grinders, and in novel means for adjusting the relative angular positions of the grinders to vary the angle of bevel produced on the knife edge, and in novel means for independently adjusting the grinders relatively to the plane of travel of the knife to compensate for unequal wear of the two grinders.

A further feature of the invention consists in the provision of gaging means for with reference to the accompanying drawings and pointed out in the claims.

In the drawings, I

Figure 1 is a side elevation, partly broken out and in section, of the essential parts of a belt knife splitting machine having my improvements Fig. '2 is a plan view of an adjustment securing member;

Fig. .3 is a detail elevation looking from the right of Fig. 1. j

So much of the rigid frame-work of a belt knife leather splitting machine as is necessary for present purposes is indicated at 10. A special machine of the type re ferred to is illustrated in the application for belt knife splitting machine filed in the name of W. C. Baxter, Serial No. 307,093.

The upper and lower stretches of the belt knife are indicated in section at 11 in Fig. 1. It is to be understood that in the present machine the belt knife is stationary so far as any adjustment is concerned. That is, it does not move forward or backward from the position indicated in Fig. 1. The feed rolls 12, 13, however, are adjusted relatively to the knife, for the special purpose of compensating for wearing away of the knife. As will be presently understood, the grinding mechanism and the feed rolls are simultaneously adjusted relatively to the edge of the knife 11. j

. The feed rolls have their bearings in a head 14 which is adjustable in suitable ways 15 of the frame 10. A bracket 16 depends from the head 14:. A lug 17 rigidly connected with the head 14 and bracket 16 is internally threaded to receive one portion of a differentially threaded screw 1.8, the outer portion of which engages an internally threaded portion of a bracket 19 suitably secured, as by bolts 20, to the rigid frame 10. Secured to the outer end of screw 18 is a ratchet wheel 21, a suitable hood 22 being provided to protect the member 21. By means of a handle 23 connected with a pawl 24 mounted in an oscillatory block 25, the ratchet wheel and the screw 18 can be manually operated as hereinafter described to adjust the head 14 and the feed rolls and the bracket 16 carrying the grinders, relatively to the upper and lower runs or stretches of the knife respectively.

The bracket 16 is formed or provided with segmental ways 26, 27 to which are fitted adjustable segmental plates 28, 29, each having slots 30 through which screws or bolts 31 pass into the ways 26, 27, binding nuts 32 being employed to hold the parts in position when adjusted. The ways 26, 27 are curved on the arcs of circles whose centers coincide with the cutting edge of the knife 11.

The upper plate 28 is formed or provided with an internally threaded bearing or socket 33 supporting an externally threaded sleeve 34 the internal portion of which forms a bearing for a shaft 35 having a pulley 36 at its upper end and provided at its lower end with an externally threaded disk to which is fitted an internally threaded ring 37 to clamp the base of the upper ring or cup-shaped grinder 38 against said disk of the shaft 35.

The lower ring or cup-shaped grinder 39 which is located at one side of the grinder 38 along the lower stretch of the belt knife 11 is secured upon the flange 40 of a tubular shaft 41 by means of a clamp ring 42. Ball bearing mechanism 43 is located between the under surface of the flange 40 and the upper end of a sleeve bearing 44 which is externally threaded, and is internally smooth to provide a bearing for the tubular shaft 41. The threaded portion of the sleeve 44 engages an internally threaded aperture in a bearing or socket 45 carried by the adjust able plate 29. To facilitate longitudinal adjustment of the sleeve bearing 44 by rotating it in the socket 45, the upper end of said sleeve 44 is provided with an annular handle 46. A similar annular handle 47 is carried by the upper sleeve bearing 34. It will now be understood that by means of the handles 46, 47 the bearings or sleeves 44, 34 can be adjusted longitudinally so as to vary the positions of the grinders relativelv to the lower and upper surfaces of the blade or knife 11. To hold the sleeve bearings in the positions to which'they are adjusted, each of them is provided with suit able means such as a clamp nut 48. This 7 clamp nut, as best illustrated in Fig. 2, may

consist of a split ring reduced in thickness or weakened as at 49 so that the two halves may yield, the opposite side of the ring being formed with cars 50 through which a right and left hand screw 51 passes, said screw being provided with a handle 52. By moving the handle 52 in one direction, the clamp nut 48 will open sufficiently to enable the sleeve bearing to be rotatably adjusted to raise or lower the grinder and then the clamp nut 48 may be actuated to lock the sleeve by movement of the handle 52 in the opposite direction. A similar clamp nut is provided for securing the upper grinder after it has been lowered or raised by actuation of the annular handle 47.

The shaft 40 is tubular in order that dust and other particles may be removed readily from the grinding point by means of any suction apparatus connected to the lower end of said shaft. Secured to the lower portion of the shaft 41 is a pulley 53 upon which a belt 54 is mounted, said belt passing over a pulley 55 carried by shaft 56, then over a pulley 57 carried by shaft 58, around the pulley 36, then back over another pulley on shaft 58 and around another pulley on shaft 56 to and around a driving pulley 59 carried by a suitably driven shaft 60.

Gages 61, 62 pivotally supported at 63, 63 by the adjustable plates 29, 28, respectively, are provided with springs 64 normally holding them in position determined by a stop 65 one of which is provided for each gage. Each gage has an indicating shoulder or edge 66 to coact with an indicating point 67 for a purpose hereinafter described.

The operation of the mechanism is as follows In a belt knife splitting machine of the type for which the present invention is designed as an attachment, the cutting edge of the knife is intended to permanently occupy travel relatively to the rolls in a vertical plane indicated by the dotted line :0, and the distance between this line and a vertical line drawn through the axes and the nip of the rolls 12, 1.3 is usually about of an inch, said distance being commonly known as the offset. The upper run of the knif coiiperates with the feed rolls while the lower run is acted upon by the two grinders 38, 39 which are preferably cupshaped and consequently have flat acting surfaces. Said grinders are so mounted that their axes are slightly inclined to each other. As the knife wears away, the feed rolls are adjusted toward the knife by actuation of the screw 18, this adjustment also correspondingly shifting the grinders so that the point where the inclined edges of the grinders cross each other, said point being indicated at 3 will shift correspondingly with the shifting of the feed rolls. Consequently when the feed rolls are adjusted toward the knife, the grinders are adjusted in the same direction an equal amount.

To vary the angle at which either grinder may operate upon the knife, the plate 28 or tion of the gages 61, 62. As these gages operate exactly alike, the operation of the gage 61 only will be described. The vmoimting and adjustment of the parts is such that when the grinder 39 is properly-locatedso that it :will grind the knife to a pointso that thecutting'edge will be exactly in line with the mid thickness of theknife, rotation of the gage61 uponits pivot 63 until the tip ofthe gage 61-bears upon'the edgeof the grinder, will cause the indicating .edge 66 of the gage to register with the point .or indicator 67. If the edge'66 does notaccurately register with the po1nt'67 when the gagehas been swung as described, .then the operator rotates the'sleeve 44 (after. loosening the nut 48) until the edge of thegrinder .39 'is in such position that when the tip of the gage 61 is in contact with said edge of the grinder, then the ga e edge 66 will register with the point .67. Byjthis means the operator .can at any timetell whether the grinders are in proper positions by manipulating the gages 61, 62.

When the grinders have beenadjusted in their proper positions longitudinally and angularly, and the knife is to be "sharpened, the operator elfectsfine adjustment of the grinders and feed rolls .toward the-knifeby operating the handle 23. Said handle is pivotally connected to the lower end of the stem 68 of pawl 24, and has a cam surface 69. A spring 70 mounted in block 25 tends to yieldingly hold the pawl 24 in engagement with the teeth of ratchet wheel 21. Fixed stops 71 limit the oscillation of block 25 which is hung upon the outer end of screw 18 by an arm or link 72. Whenthe operator swings the block 25 by means of handle 23 while the latter is in the position shown in Fig. 1, the pawl 24 effects a very gra duallactuation of the screw 18 towhatever extent is necessary to bring the grinders into effective position to sharpen the-knife. The same operation causes the feed rolls to move to the same extent so that the hip or bite of the rolls will be at the proper distance from the edgeof the upper run of the knife. p

There are, of course, times when it is necessary to back off or separate the grinders and feed rolls from proximity to the knife, such as when a worn out belt-knife is to be replaced by a new one. To effect this, the operator throws the handle 23 down to a vertical or pendant position which causes its cam portion 69 to so bear on the bottom of block 25 as to withdraw the pawl 24 from the ratchet wheel and leave the latter -free to be rotated byha suitable wrench 73 which is indicated only by dotted lines in Fig. 1 because it is not intended to leave said wrench permanently in place.

-To aid in so adjusting the plates 28, 29, that therflat faces of the two grinders will operate in corresponding angular planes on the opposite vsides of the knife edge, the .xbrackehlfi is provided with pins havingindicating points 7 4 to cooperate with suitable scale marks'ca-rried by the plates 28, 29, the latter havingarcslots 75 through whichthe indicatorpins project.

It wills be readily. understood that. inv the use of a machine of this character the operator would not be able to see ,any difference iin'the len th of the. bevels ion, the opposite surfacesoi the knife edge,.unless such difference is excessive. Nor. could he see that the edge ofthe knife is.v too far. back from the bite or nip ofthe feed rolls. By' employing the'pivotedgages 6l, 62, he can inform him- .selfas to either or .both -,of; thesaid questions merely by manipulating the gages in the manner I described, :and then effecting any unecessary ad ustment resulting from the .use

.ofthe gages.

Having..idescribed my invention, what I 1 claim as new and :desire to secure by Letters Batent of the. United States-is 1. Aagrindingattachment for-a belt knife splitting machine, comprising. a'pair' of opl positelyfacing fiat-surfaced grinders, oppositely extending grinders, and means for simultaneously ading work to the knife, flat-faced grinders for operating -;upon the knife, and means for simultaneously adjusting the feed rolls and the grinders relatively, to the cutting edge of the knife.

t3. In a .machine of the character described, in; combination, a beltknife, rolls for feedingwork to one stretch of the knife, fiatfaced grinders for operating .upon the other stretch of the knife, and means for simultaneously adjusting-thefeed rolls and the grinders relatively to-those portions of the vknife with. which they cooperate.

. 4. In a machine vof the class described, in combination, arbeltknife, ,a pair. ofrot-ary flat-fafi i grinders, ,drive shafts'for the grinders having their axes slightly inclined relatively to each other and to the knife, and means for simultaneously adjusting the grinders toward the edge of the knife without altering their angular relationship.

5. In a machine of the character described, in combination, a belt knife, a pair of rotary fiat-faced grinders having their axes slightly inclined relatively to each other and to the knife, oppositely extending drive shafts for the grinders, and means for adjusting the angular relationship of said grinders.

6. In a machine of the character described, in combination, a belt knife, a air or rotary flat-faced grinders, having t eir axes slightly inclined relatively to each other and to the knife,.means for adjusting said grinders longitudinally of their axes of rotation, and means for adjusting the grinders in arcs of circles whose centers coincide with the cutting edge of the knife.

7. In a machine of the class described, in combination, a belt knife, a grinder for the cutting edge of the knife, means for adjustin the grinder relatively to the knife, and a finger for engaging the working surface of the grinder for indicating the amount of adjustment necessary to effect proper action of the grinder upon the knife.

8. In a machine of the character described, in combination, a belt knife, a pair of rotary flat-faced grinders having their axes slightly inclined relatively to each other and to the knife, means for adjusting said grinders longitudinally of their axes of rotation, and gage devices including fingers for engaging the grinders to insure equal bevels on the knife by indicating the amount of adjustment necessary to effect roper action of the grinders upon the kni e.

9. In a machine of the character described, in combination, a belt knife, a pair of fiat-faced grinders mounted to equally bevel opposite surfaces of the knife, and means for adjusting the grinders in arcs of circles whose centers coincide with the meeting line of the two bevels.

10. In a machine of the character described, in combination, a belt knife, a pair of fiat-faced grinders mounted to equally bevel opposite surfaces of the knife, means for adjusting the grinders in arcs of circles whose centers coincide with the meeting point of the two bevels, and gage devices for determining if the grinders are in accurate positions relatively to said point.

11. In a machine of the character described, in combination, a belt knife, a head carrying rolls for feeding work to the knife, a bracket connected with said head, means for simultaneously adjusting the head and bracket relatively to the plane of operation of the knife, curvilinearly adjustable plates carried by said bracket, and flat-faced grinders rotatively mounted in said lates.

12. In a machine of the character described, in combination, a belt knife, a head carrying rolls for feeding work to the knife, a bracket connected with said head, means for simultaneously adjusting the head and bracket relatively to the plane of o eration of the knife, curvilinearly adjustab e plates carried by said bracket, grinders rotatably mounted in said plates andmeans for adjusting said grinders longitudinally of their axes of rotation. 13. In a machine of the character described, in combination, a belt knife, and a pair of rotary flat-faced grinders having their axes inclined relatively to each other, one of said grinders having a tubular shaft for the escape of fine material removed from the knife by the grinders.

14. In a machine of the character described, in combination, a belt knife, a supporting member having an opening for the passage of One run of the knife, saidv supporting member having curved ways, bearing members adjustable along said ways, and a pair of rotary fiat faced grinders having gheir shafts mounted in said bearing memers.

15. In a machine of the character described, in combination, a belt knife, a pair of oppositely facing flat faced grinders mounted to act on opposite surfaces of one run of the belt knife, means for longitudinally adjusting the grinders, and a pair of gages for determining the plane of operation of the actin faces ofthe grinders.

16. In a mac ine of the character described, in combination, a belt knife, a pair of oppositely facing flat faced grinders mounted to act on opposite surfaces of one run of the belt knife, means for longitudinally adjusting the grinders, a pair of pivoted fingers adapted to be manually operated to contact with the facesof the grinders,

springs for normally holding said fingers in inoperative positions, and scales to cooperate with said fingers when the latter are manually operated to determine the amount of adjustment necessary to effect proper action of the grinders upon the knife.

In testimony whereof I have signed my name to this specification.

LLOYD G. KNOWLES. 

